Nectarine tree named ‘Burnectfour’

ABSTRACT

A new and distinct variety of nectarine tree substantially as illustrated and described and which produces an attractively colored yellow-fleshed clingstone nectarine which is mature for harvesting and shipment approximately September 8 to September 18 under the ecological conditions prevailing in the San Joaquin Valley of Central California.

BACKGROUND OF THE NEW VARIETY

Botanical Classification: Prunus persica.

Variety Denominaton: ‘BURNECTFOUR’.

The present invention relates to a new, novel and distinct variety ofnectarine tree, Prunus persica var. (nucipersica), which has beendenominated varietally as ‘Burnectfour’. The present variety ofnectarine tree resulted from an on-going program of fruit and nut treebreeding. The purpose of this program is to improve the commercialquality of deciduous fruit and nut varieties and rootstocks by creatingand releasing promising selections of prunus, malus and regia species.To this end we make both controlled and hybrid cross pollinations eachyear in order to produce seedling populations from which improvedprogenies are evaluated and selected.

The seedling ‘Burnectfour’ was originated by us from a population ofseedlings grown in our experimental orchards located near Fowler, Calif.The seedlings, grown on their own roots, were the result of a controlledcross of the nectarine tree ‘September Red’ (U.S. Plant Pat. No. 5,664)used as the seed parent, and the nectarine tree ‘Spring Bright’ (U.S.Plant Pat. No. 7,507) which was used as the pollen parent. One seedling,which is the present variety, exhibited especially desirablecharacteristics and was marked for subsequent observation. After the1996 season, the new, present variety was selected for advancedevaluation and repropagation.

ASEXUAL REPRODUCTION

Asexual reproduction of the new and distinct variety of nectarine treewas made by budding same to ‘Nemaguard’ Rootstock (non-patented). Thiswas performed by us in our experimental orchard located near Fowler,Calif. Subsequent evaluations have shown that those asexualreproductions run true to the original tree. All characteristics of theoriginal tree and its fruit were established and appeared to betransmitted through succeeding asexual propagations.

SUMMARY OF THE VARIETY

‘Burnectfour’ is a new and distinct variety of nectarine tree, which isof medium to large size, has vigorous growth, and is a regular andproductive bearer of large, firm, yellow flesh, semi-freestone fruitwith good flavor and eating quality. The tree has a medium-chillingrequirement of approximately 600 hours. The tree also producesrelatively uniformly sized fruit throughout the tree, with a high degreeof red color, and firm flesh. The fruit appears to have good handlingand shipping quality. The ‘Burnectfour’ nectarine tree bears fruit thatis ripe for commercial harvesting and shipment on approximatelySeptember 8 to September 18 under ecological conditions prevailing incentral California. In comparison to the parent ‘September Red’Nectarine (U.S. Plant Pat No. 5,664), the new variety ripens 10 or moredays later.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawing shows two whole fruit; a half fruit with thepit exposed revealing an equatorial (ventral view); one vegetative shootwith typical leaves and one pit. Two of the fruit show their externalcoloration sufficiently matured for harvesting and shipment. The colorsare as nearly true as is reasonably possible in a color photographicrepresentation of this type. Due to chemical development, processing andprinting of the photographic image, the leaves, pit and fruit depictedin this photograph may or may not be accurate when compared to theactual botanical specimen. For this reason, future color referencesshould be made to the color plates (Royal Horticultural Society) anddescriptions provided hereinafter.

DETAILED DESCRIPTION

Referring more specifically to the pomological details of this new anddistinct variety of nectarine tree, the following has been observedduring the fifth fruiting season under the ecological conditionsprevailing at the orchards located near the town of Fowler, county ofFresno, state of California. All major color code designations are byreference to The R.H.S. Colour Chart (Fourth Edition) provided by TheRoyal Horticultural Society of Great Britain.

Tree:

Size.—Generally. — Considered medium as compared to other commoncommercial nectarine cultivars ripening in the mid season of maturity.The tree was pruned to a height of about 304.8 cm to about 365.7 cm atmaturity.

Vigor.—Moderately vigorous. The variety grew from about 131.92 cm to192.8 cm in height the first growing season. The variety was pruned to aheight of about 106.7 cm during the first dormant season and primaryscaffolds were then selected for the desired tree structure.

Productivity.—Considered productive.

Bearer.—Regular. Fruit set has been heavy and thinning was necessaryduring the past 4 years.

Form.—Upright, and pruned to a vase shape.

Density.—Medium dense. It has been discovered that pruning the branchesfrom the center of the tree to obtain a vase shape allows for airmovement and sunlight to enhance fruit color and renewal of fruitingwood throughout the tree.

Hardiness.—The present tree was grown and evaluated in USDA HardinessZone 9. Winter chilling requirements for this tree are approximately 600hours below 7.0 degrees C. The variety was considered hardy undertypical Central San Joaquin Valley conditions.

Trunk:

Diameter.—Approximately 17.0 cm in diameter when measured at a distanceof approximately 15.24 cm above the soil level, at the end of the fifthgrowing season.

Bark texture.—Considered moderately rough with numerous folds of paperyscarfskin being present.

Lenticels.—Numerous flat, oval lenticels are present. The lenticelsrange in size in size from approximately 2.0 to 5.0 millimeters inwidth, and from 1 to 2 millimeters in height.

Lenticel color.—Considered an Orange Brown. (RHS Greyed-Orange N172 A).Bark Coloration. — Variable, but it is generally considered to be agrey-brown (RHS Greyed-Orange Group 177 A.

Branches:

Size.—Considered medium for the variety.

Diameter.—Average as compared to other varieties. The branches have adiameter of about 80.0 millimeters when measured during the fifth yearafter grafting.

Surface texture.—Average, and appearing furrowed on wood which isseveral years old.

Crotch angles.—Primary branches considered variable between about 45 to49 degrees from the horizontal axis. This characteristic is notdistinctive of the variety, however.

Current season shoots.—Surface texture — Substantially glabrous.

Internode length.—Approximatley 2.3 to 2.4 cm.

Color of mature branches.—Medium brown, (RHS Grey Brown Group N199 C).

Current seasons shoots.—Color. — Light green, (RHS Yellow Green Group144 C). The color of new shoot tips is considered a bright and shinygreen (RHS Green Group 134 C).

Leaves:

Size.—Considered medium for the species. Leaf measurements have beentaken from vigorous upright current growth at approximately mid-shoot.

Leaf length.—Approximately 140 to 170 millimeters.

Leaf width.—Approximately 36 to 43 millimeters.

Leaf base shape.—Slightly oblique relative to the leaf longitudinalaxis.

Leaf form.—Lancelolate.

Leaf tip form.—Acuminate.

Leaf color.—Dark green, (RHS Yellow Green Group 146 B).

Leaf texture.—Glabrous.

Lower surface.—Medium green, (RHS Yellow-Green Group 145 A).

Leaf venation.—Pinnately veined.

Mid-vein.—Color. — Light yellow green, (RHS Yellow Green Group 145 D).

Leaf margins.—Slightly undulating. Form. — Considered crenate,occasionally doubly crenate. Uniformity. — Considered generally uniform.

Leaf petioles.—Size. — Considered medium long to long. Length. — 9.0 mmto about 12.0 mm. Diameter. — 1.5 mm to about 2.5 mm. Color. — Palegreen, (RHS Yellow Green Group 145 D).

Leaf glands.—Size. — 1.0 mm in height and about 1.0 to 2.0 mm in width.Numbers. — Generally one per side, occasionally two per side. Type. —Globose, and considered reasonably unappressed to the petiole margin.Color. — Greenish brown (RHS Yellow Green Group152 B).

Leaf stipules.—Size. — Medium large for the variety. Number. — Typically2 per leaf bud, and up to 6 per shoot tip. Form. — Lanceolate in form,and having a serrated margin. Color. — Green (RHS Green Group 132 A)when young but graduating to a yellow-brown color (RHS Grey Orange group177 A) with advancing senescence. The stipules are considered to beearly deciduous.

Flowers:

Flower buds.—Generally — The floral buds are considered to be large,about 15 millimeters wide, and about 21 millimeters long; conic in form;and slightly appressed relative to the bearing shoot.

Flower buds.—Color — The bud scales are gray-brown, (approximately RHSGreyed Purple Group 183 A). The buds are considered hardy under typicalcentral San Joaquin Valley climatic conditions.

Hardiness.—No winter injury has been noted during the last several yearsof evaluation in The Central San Joaquin Valley. The current variety hasnot been intentionally subjected to drought or heat stress and thereforethis information is not available.

Date of first bloom.—Feb. 22, 2000.

Blooming time.—Considered early in relative comparison to othercommercial nectarine cultivars grown in the Central San Joaquin Valley.The date of full bloom was observed on Mar. 2, 2000. The date of bloomvaries with climatic conditions.

Duration of bloom.—Approximately 8 days.

Flowers type.—The variety is considered to have a showy type flower.

Flower size.—Flower diameter at full is approximately 31.0 to 36.0millimeters.

Bloom quantity.—Considered abundant.

Flower bud frequency.—Normally 1 to 2 appear per node.

Petal size.—Generally — Considered medium large to large for thespecies. Length. — Approximately 16.0 to 19.0 millimeters. Width. —Approximately 17.0 to 19.0 millimeters.

Petal form.—Broadly ovate.

Petal count.—Nearly always 5.

Petal texture.—Glabrous.

Petal color.—Light pink when young, (RHS Red Purple Group 65 B), anddarkening with advancing senescence and exposure to sunlight to a mediumto dark pink (RHS Red Purple Group 65 A).

Fragrance.—Slight.

Petal claw.—Form. — The claw is considered truncate and has amedium-large size when compared to other varieties. Length. —Approximately 8.0 to 10.0 millimeters. Width. — Approximately 6.0 to 8.0millimeters.

Petal margins.—Generally considered variable, from nearly smooth, tomoderately undulate and ruffled, especially apically.

Petal apex.—Generally — The petal apices appear slightly domed.

Flower pedicel.—Length. — Considered medium-long, and having an averagelength of approximately 3.0 to 5.0 millimeters. Diameter. — Consideredaverage, approximately 2.0 millimeters. Color. — A medium Green (RHS —Grey Brown Group N199 D).

Floral nectaries.—Color. — A dull orange-gold ((RHS Greyed Red Group 178B).

Calyx.—Surface Texture. — Generally glabrous. Color. — A dull red,(approximately RHS Greyed Purple Group 183 A).

Sepals.—Surface Texture. — The surface has a short, fine, wooly and agray colored texture. Size. — Average, and ovate in form. Color. — Adull red, (approximately RHS Greyed-Red Group 178 A).

Anthers.—Generally. — Average to above average in length. Color. — Redto reddish-orange dorsally, (approximately RHS Greyed Purple Group 179A).

Pollen production.—Pollen is abundant, and has a yellow color,(approximately RHS Yellow Orange Group 17 B).

Filaments.—Size. — Variable in length, approximately 11.0 to 13.0millimeters in length. Color. — White, (RHS Red Purple Group 62 D).

Pistil.—Number. — Usually 1, rarely 2. Generally. — Average in size.Length. — Approximately 14.0 to 16.0 millimeters including the ovary.Color .— Considered a very pale green, (approximately RHS Yellow GreenGroup 151 D). Surface Texture. — The variety has a long, glabrous, palegreen to whitish-yellow colored pistil.

Fruit:

Maturity when described.—Firm ripe condition (shipping ripe); Date offirst picking. — Sep. 8, 2000. Date of last picking. — Sep. 18, 2000.The date of harvest varies slightly with climatic conditions.

Size.—Generally — Medium large, and considered uniform.

Average cheek diameter.—Approximately 73.0 to 75.0 millimeters.

Average axial diameter.—Approximately 71.0 to 73.0 millimeters.

Typical weight.—Approximately 231.0 grams. This is highly dependent oncultural practices and is therefore not distinctive of the variety.

Fruit form.—Generally — Moderately oblate. The fruit is generallyuniform in symmetry.

Fruit suture.—Shallow, slightly lipped, and extending from the base tothe apex. No apparent callousing or stitching exists along the sutureline.

Suture.—Color — This appears to have a yellow to golden yellowbackground color, (approximately RHS Yellow Orange Group 26 B) with somered orange color (approximately RHS Red Group 46 B).

Ventral surface.—Form — Slightly indented.

Apex.—Rounded.

Base.—Retuse.

Stem cavity.—Rounded too slightly enlongated in the suture plane.Average depth of the stem cavity is about 1.25 cm. Average width isabout 2.51 cm.

Fruit skin.—Thickness. — Considered medium in thickness and tenacious tothe flesh. Texture. — Glabrous. Taste. — Non-astringent. Tendency tocrack. — None observed.

Fruit skin color. —Blush Color. — This red blush color is variable,(approximately RHS Red Orange Group 46 A to 45 B). Ground Color. —Yellow orange (approximately RHS Orange Group 26 B).

Fruit stem.—Medium in length, approximately 8.0 to about 9.0millimeters. Diameter. — Approximately 2.0 to 3.0 millimeters. Color. —Pale yellow-green (approximately RHS Yellow Green Group 145 B).

Flesh.—Ripens. — Evenly. Texture. — Firm and dense. Fibers. — Few, smalland tender. Aroma. — Very slight. Eating Quality. — Good. Flavor.—Considered sweet and mildly acidic. The flavor is considered bothpleasant and balanced. Juice. — Moderate. Brix. — 11.0 degrees. Variesslightly with the number of fruit per tree, cultural practices, andclimatic conditions. Flesh Color. — Yellow, (approximately RHS YellowOrange Group 22A).

Stone:

Type.—Clingstone.

Size.—Considered medium for the variety.

Length.—Average about 22.0 to 24.0 millimeters.

Width.—Average about 21.0 to 22.0 millimeters.

Diameter.—Average about 18.0 to 19.0 millimeters.

Form.—Obovoid.

Base.—The stone is usually rounded, but it varies from rounded tostraight.

Apex.—Shape. — The stone apex is raised and has an acute, short, tip.

Stone surface.—Surface Texture — Irregularly furrowed toward the apex,and pitted toward the base. The stone exhibits substantial pittinglaterally. Substantial grooving over the apical shoulders is evident.Surface pitting is prominent generally, and more frequently, it ispresent basally. One long furrow on each side of suture will normally befound. Ridges. — Surface texture varies from sharp to rounded. VentralEdge. — Width — Considered medium, and having a dimension ofapproximately 5 to 6.5 millimeters at the mid-suture. The wings are mostprominent over the basal area. Dorsal Edge. — Shape. — Full, heavilygrooved, and having jagged edges. The dorsal edge is moderately erodedover the apical shoulder.

Stone color.—The color of the dry stone is a light to medium brown,(approximately RHS Greyed Orange Group 166 B).

Tendency to split.—Few but very infrequent splitting noted.

Kernel.—Size.— Length — 17.0 mm. Width — 12.0 mm. Thickness — 3.0millimeters. Form. — Obovoid. Pellicle. — Pubescent. Color .— (RHSGreyed Orange Group 173 B).

Use.—The subject variety ‘Burnectfour’ is considered to be a Nectarineof the late-season maturity, and which produces fruit which are veryfirm, attractively colored, and which are useful for both local and longdistance shipping.

Keeping quality.—Excellent. Fruit has stored well up to 21 days afterharvest at 1.0 degree Celsius.

Shipping quality.—Good. Fruit of the present variety showed minimalbruising of flesh or skin damage after normal harvest and packingprocedures.

Resistance to insects and disease.—No particular susceptibilities werenoted. The present variety has not been subjected to testing todetermine any susceptibilities or resistances to known plant and orfruit diseases.

Although the new variety of nectarine tree possesses the describedcharacteristics when grown under the ecological conditions prevailingnear Fowler, Calif., in the Central part of the San Joaquin Valley ofCalifornia, it will be understood that variations of the usual magnitudeand characteristics incident to changes in growing conditions,fertilization, pruning, pest control and horticultural management are tobe expected.

Having thus described and illustrated our new variety nectarine tree,what we claim is new and desire to secure by Plant Letters Patent is: 1.A new distinct variety of nectarine tree substantially as illustratedand described and which is characterized principally as novelty byproducing an attractively colored yellow-fleshed clingstone nectarinewhich is mature for harvesting and shipment approximately September 8 toSeptember 18 under the ecological conditions prevailing in the SanJoaquin Valley of Central California.